Wireless communication system and method for trains and other vehicles using trackside base stations

Abstract

A method and system for wireless communication with a mobile router in a moving vehicle, such as a train, and an external wireless network is disclosed. The external network includes a plurality of trackside base stations distributed along a path of travel. The method includes: determining the presence of a mobile router within the access area of a trackside base station, and when the presence of a mobile router has been determined: setting the power of the trackside base station to a high power mode; determining a direction of travel of the vehicle; setting the power of at least one trackside base station arranged in the forward direction of the base station for which the mobile router has been detected to a high power mode; and setting the power of at least one trackside base station arranged in the backward direction of the base station to a low power mode.

The invention claimed is: 
     
       1. A method for wireless communication with a mobile router in a moving vehicle and an external wireless network comprising a plurality of trackside base stations, said base stations distributed along a vehicle path of travel, the method comprising:
 determining the presence of a mobile router within the access area of any of said plurality of trackside base stations, and when the presence of a mobile router has been determined:
 setting the power of said trackside base station for which the mobile router has been detected to a high power mode; 
 determining a direction of travel of said vehicle; 
 setting the power of at least one trackside base station arranged in the forward direction of the base station for which the mobile router has been detected, as seen in the determined direction of travel, to a high power mode; and 
 setting the power of at least one trackside base station arranged in the backward direction of the base station for which the mobile router has been detected, as seen in the determined direction of travel, to a low power mode. 
 
 
     
     
       2. The method of  claim 1 , wherein the mobile routers are arranged to receive GNSS data, and communicate this to the external mobile network, said GNSS data being useable to detect the presence of the mobile router within the access area of any of said plurality of trackside base stations. 
     
     
       3. The method of  claim 1 , wherein both the mobile routers and the trackside base stations are in communication with a control server, said server comprising information of the positioning of the trackside base stations, and being arranged to control the trackside base stations to assume either of the low and high power modes. 
     
     
       4. The method of  claim 3 , wherein the mobile routers are arranged to send information to the control server about their present positions. 
     
     
       5. The method of  claim 3 , wherein the trackside base stations are arranged to send information to the control server about mobile routers being determined to be within their access area. 
     
     
       6. The method of  claim 3 , wherein the control server is arranged to determine the direction of travel of each mobile router based on the position data from each mobile router. 
     
     
       7. The method of  claim 3 , wherein the control server is arranged to determine the direction of travel of each mobile router by the sequence of trackside base stations in which the mobile routers are present. 
     
     
       8. The method of  claim 1 , wherein the low power mode is set to such a power that communication with mobile routers is still possible, at least at close range. 
     
     
       9. The method  claim 1 , wherein the mobile router is arranged to simultaneously communicate with the external mobile network through at least two trackside base stations when more than one trackside base station are accessible for the mobile router, thereby providing two concurrently useable data links. 
     
     
       10. The method of  claim 1 , wherein the mobile router is further arranged to simultaneously communicate with at least one further external wireless network, thereby providing at least one further concurrently useable data link. 
     
     
       11. The method of  claim 10 , wherein the mobile router is arranged to evaluate the quality of said data links; and
 assigning data streams to said data links at least partly based on said evaluated quality. 
 
     
     
       12. The method of  claim 1 , wherein all the trackside base stations, as a default are operated in a low power mode. 
     
     
       13. A computer-readable storage medium encoded with instructions for executing in a wireless device the instructions, when executed, performing a method as defined in  claim 1 . 
     
     
       14. A wireless communication system for wireless communication between a mobile router in a moving vehicle and an external wireless network comprising a plurality of trackside base stations, said base stations distributed along a vehicle path of travel, the system comprising a controller including a processor being connected to the trackside base stations, and list of said plurality of trackside base stations and the operational state of said trackside base stations, wherein the control is arranged to:
 determining the presence of one or several mobile router(s) within the access area of any of said plurality of trackside base stations; 
 updating the operational state of the base station in said list in accordance with this determination, so that all trackside base stations having a mobile router in their coverage area(s), and at least one trackside base station ahead and behind this base station, respectively, are set in one or several high power mode(s), and other trackside base stations are set in a low power mode; 
 sending control instructions to the trackside base stations to assume the determined operational states in accordance with the updated list.